15 Heart-Stopping Skywalks That Will Turn Your Legs To Jelly

A few weeks ago, we showed you a terrifying Alpine tourist attraction called "Step Into the Void." It's a glass cage that hangs more than 3,300 feet above the mountains. But the Void is hardly the first heart-stopping skywalk—in fact, these are dozens out there that are just as scary.

I'm not afraid of heights, but I don't know how would I react to "Step Into the Void." Experts say that our brains get a bit confused in such environments, and often need some time to acclimate to the new, physics-defying situation it's in. Even if you're not near the Alps, you can test yourself below—we've collected 15 similar skywalks from around the globe. Enjoy the view!

Spectators look at the city from a walkway perched a dizzying 268 meters (880 feet) up a landmark downtown tower in Sydney, Australia. The "Skywalk" is a 160-meter (525 feet) circuit running around the Sydney Tower.

Photo: Skywalk/AP

Tourists walk on the Grand Canyon Skywalk. Operated by the Hualapai Indian tribe, at 1219 m (4000 ft), the Grand Canyon Skywalk is the second highest glass floor on Earth.

A visitor to the glass Skywalk at the top of the 158 meters (519 ft) high Blackpool Tower in Blackpool, UK.

Looking down through the glass floor of the 170 m (560 ft) high Spinnaker Tower in Portsmouth, UK.

Here, a girl looks down from "The Ledge," Chicago's 442 meter (1450 ft) high Willis Tower. The glass balcony is suspended 1353 feet in the air and juts out four feet from the Sears Tower's 103rd floor Skydeck.

Photo: Kiichiro Sato/AP

And here's the glass cage named "Pas dans le Vide" (Step into the Void) at the top of the Aiguille du Midi peak (3842 meters high or 12,604 feet) that I mentioned earlier. Visitors can enjoy the view of Mont Blanc, Europe's highest mountain, from the platform, which just ousted the Grand Canyon Skywalk as the highest glass floor above ground on Earth.

Photo: Alexis Moro/AP

Here's the view from the first floor of the 540 meter (1772 ft) tall Ostankino TV Tower, Moscow, Russia.